Method and apparatus for cementing and conditioning bore holes



Dec. 6, 1966 A. w. KAMMERER METHOD AND APPARATUS FOR CEMENTING AND CONDITIONING BORE HOLES I5 Sheets-Sheet 1 Filed Feb. 10, 1964 Ear- 0 E00 20 0;? 200 4'0 INVENTOR.

Dec. 6, 1966 A. w. KAMMERER METHOD AND APPARATUS FOR CEMENTING AND CONDITIONING BORE HOLES 5 Sheets-Sheet 2 Filed Feb. 10, 1964 INVENTOR- flecmsz m KQMMEEER Dec. 6, 1966 METHOD AND APPARATUS FOR CEMENTING AND CONDITIONING BORE HOLES Filed Feb. 10, 1964 A. W- KAMMERER 55 Sheets-Sheet 3 INVENTOR. flea/5e W K/QMMEEEE United States Patent 3,289,760 METHOD AND APPARATUS FOR CEMENTING AND CONDITIONING BORE HOLES Archer W. Kammerer, Fullerton, Califi, assignor of onefifth to Archer W. Kammerer, Jr., Houston, Tex., and one-fifth to Jean K. Lamphere, Fullerton, Calif.

Filed Feb. 10, 1964, Ser. No. 343,625

15 Claims. (Cl. 166-21) The present invention relates to methods and apparatus the exposed well bore washed or otherwise conditioned,

and cement deposited in the well bore along part or all of its exposed length to form a cementitious plug therein, all of the abovesteps being performed with a single round trip of well apparatus in the bore hole.

As an example, a cement plug is required to support a whipstock used for subsequent hole deflection or deviation operations, However, before the whipstock is set, a portion of the cement plug may require removal by a drilling operation. In addition, it is desirable for the cement coating formed on the wall of the casing or liner during the cementing operation above the milled away section to be scraped oft" to prevent its potential interference with subsequent operations in the bore hole. Even in the absence of any need to drill out a portion of the plug, the cement coating formed on the Wall of the casing or liner, which may have resulted from flushing excess cement from the latter, should preferably be removed.

Such drilling out, scraping, or both operations have heretofore been performed with appropriate equipment requiring separate round trips in the well bore, which consumes substantial additional time and adds greatly to the cost of obtaining a final desired well bore condition, the increased cost resulting from the cost of the equipment in addition to the value of the time consumed in effecting its running in and out of the well bore.

It is an object of the present invention to provide methods and apparatus for milling away a desired length of casing or liner in a bore hole, accomplishing one or more other operations in the well bore, including introducing cementitious material into the exposed region of the bore hole, and drilling away a portion of the cementitious material so introduced, all with a single trip of the apparatus in the well bore.

Another object of the invention is to provide methods and apparatus for milling awaya desired length of casing or liner in a bore hole, accomplishing one or more other operations in the well bore, including introducing cementitious material into the exposed region of the well bore, and scraping the wall of the casing of liner, all with a single trip of the apparatus in the Well bore.

A further object of the invention is to provide methods and apparatus for milling awaya desired length of easing or liner in a bore hole, accomplishing one or more other operations in the well bore, including introducing cementitious material into the exposed regionof the bore hole, drilling away a portion of the cementitious material so introduced, and scraping the wall of the casing or liner, all with a single trip of the apparatus in the well bore.

This invention possesses many other advantages and has other objects which may be more clearly apparent from a consideration of a method and apparatusembodying the invention. Such method and apparatus are shown and described in the present specification and in the drawings "ice derstood that suchdetailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a diagrammaticsection through a well bore illustrating apparatus milling away a section of casing or liner in the wellbore; t 4

FIG. 2 is a view similar to FIG. 1 illustrating the conditioning or depositing of cementitious material in the well bore to form a plug therein; v 1 7 FIG. 3 is a view similar to FIGS. 1 and 2 illustrating a hardened cement plug in the well bore, and the apparatus in position for drilling out a portion of the cement plug and e for scraping the wall of the well casing or liner thereabove; I y

FIG. 4 is a view similar to FIGS. 1, 2 and 3 illustrating a portion of the cement plug drilled away;

FIGS. 5a and 5!) together constitute a longitudinal section through an apparatus used in performing the steps illustrated in FIGS. 1 to 4, with the parts in their initial or retracted position, FIG. 5b being a lower continuation of FIG. 5a;

FIG. 6 is a longitudinal section similar to FIG. 5a illustrating the cutters of the apparatus in expanded condition;

FIG. 7 is a longitudinal section, with parts shown in elevation, of the apparatus in its condition for performing the operations shown in FIGS. 3 and 4.

The invention is specifically illustrated in the drawings in connection with an apparatus A specifically designed for cutting or milling away a portion of well casing D, or other well conduit disposed in a well bore, along a desired length. The same apparatus can be used for performing a jetting action upon the. exposed well bore for the purpose of conditioning the latter, enlarging the diameter of the same, depositing cementitious material in the well bore, drilling out any excessive undesired cementitious material so deposited, or scraping the wall of the well casing, or a combination of any of the aforementioned operations.

The apparatus A is secured to the lower end of a. string of drill pipe B that extends to the top of the well bore C, and by means of which the apparatus is lowered through the string of well casing to a location therein at which a casingmilling operation is to commence, and where other operations are also to be performed without removing the apparatus from the well casing.

As disclosed most clearlyin FIGS. 5a, 5b, 6 and 7, the

apparatus A may include a rotary expansible drill bit H,

mandrel includes an upper kelly or drill stem member i 12 slidably splined to the main body 13 of the bit. The exterior of the lower portion 14 of the kelly is noncircular in shape, being telescopically received in a companion non-circular socket 15 formed in the main bit body'13. As an example, the. kelly, exterior and the socket 15 may be of hexagonal shape to enable the kelly 12 to be moved longitudinally with respect to the body 13, while still being capable of transmitting rotary motion to the body.

The mandrel 10 has a lirnitedrange of-longitudinal movement'within the body, downward movement being determined by engagement of the lower end 16 of the kelly with an inwardly directed body shoulder 17. Its upward movement is limited by engagement of an external shoulder or piston portion 18 of the kelly with a cylinder head 19 secured to the body. The upper end of the head has a flange 20 engaging a body shoulder 21, the flange being prevented from moving upwardly of the body by split snap retainer rings 22 fitting in a body groove 23 and overlying the flange 20. An annular guide 24 is releasably secured to the body 13 by a split snap ring 25 above the retainer rings 22.

The body has a plurality of expansible parts mounted on it. These include cutter supporting members 26 pivotally mounted in body slots 27 on hinge pins 28 suitably secured to the body to prevent their loss therefrom. Each cutter supporting member 26 depends from the hinge pin 28 and carries a drap or milling cutter structure 29 at its lower end, which may be welded or otherwise suitably attached to each supporting member 26.

The cutter supporting members 26 and the cutter structures 29 themselves tend to occupy a retracted position substantially entirely within the confines ofthe main body 13 of the bit. These cutter supporting members and the cutter structures are expandible outwardly to sever the casing D and mill it away by operating upon the upper end E of the casing therebelow. To accomplish the expansion, each cutter supporting member has an inclined expander surface 30 on its inner portion below the hinge pin 28 which tapers in a downward and inward direction. Each expander surface terminates in a lock surface 31 formed on a lock portion 32 of the cutter supporting member. The outward expansion is accomplished by producing relative longitudinal movement between the mandrel and the bit body 13, which will produce relative longitudinal movement between the cutter supporting members 26 and the tubular member 33 of the mandrel 10.

The tubular member includes a portion 34 slidable within a guide bushing 35 mounted in a bridge 36 secured to the body and extending across the body slot 27. This guide bushing 35 is disposed below the lock portions 32 of the cutter supporting members 26. The tubular member 33 extends downwardly of the guide bushing to a substantial extent and is piloted within a lower head portion 100 of the body below its slots 27, extending into a body chamber or central passage 101. Leakage of fluid between the mandrel 33 and the body of the tool below the slots is prevented by a suitable side seal ring 102 mounted in the body and slidably and sealingly. engaging the periphery of the mandrel or tubular member 33. Accordingly, fluid under pressure discharging from the tubular member into the body chamber 101 cannot pass upwardly out of the chamber. Instead, such fluid in the chamber passes outwardly through radial nozzels 103 capable of discharging fluid against the wall of the surrounding well bore or casing. The lower end of the chamber or passage 101 opens into a lower threaded box portion 104 of the body, that threadedly receives the upper pin 105 of the drill bit K, the fluid being capable of passing from the body or chamber into the usual fluid passage or passages 106 in the drill bit for discharge through one or a plurality of lower nozzels or outlets 107 in the latter, for the purpose of removing the cuttings produced by the drill bit and flushing them upwardly around the apparatus A and the drill pipe B to the top of the well bore.

Located initially and substantially above the guide bushing 35 and below the hinge pins 28, and in cutter member recesses 37, is a mandrel lock and expander 38 which has outer surfaces 39 adapted to engage the expander surfaces 30 and lock surfaces 31. The lock and expander 38 may be formed integrally with the tubular member 33, the upper end of the latter being piloted within a socket 40 formed in the lower portion 14 of the kelly 12. An enlarged boss 41 on the tubular member 33 engages a downwardly facing shoulder 42 of the kelly, the tubular member being held against this shoulder by a suitable slip retainer or lock ring 43 snapped into an internal groove 44 encompassing the kelly socket and engaging the lower end of the tubular member boss 41.

Drilling mud or other fluid can pass down through the central passage 45 in the kelly or drill stem member 12 and into the central passage 46 that extends completely through the tubular member 33, this fluid or fluent material passing into the body chamber 101 and then outwardly through the radial nozzles 103 and the drill bit nozzles or outlets 107.

Assuming the body 13 of the tool to be elevated relatively along the tubular mandrel 10, the inclined expander surfaces 30 of the cutter supporting member 26 will be shifted upwardly along the lock and expander portion 38 of the tubular member 33. During such upward shifting, the cutter supporting members 26 and the cutter structures 29 carried thereby will be pivoted about the hinge pins 28 and urged in an outward direction. The upward movement of the body 13 with respect to the tubular mandrel 10 can continue until the cutter structures 29 have been shifted outwardly to their fullest extent, as determined by engagement of stop shoulders 49 on the cutter supporting members 26 with companion shoulders 50 formed in the body on opposite sides of the body slots 27 When such engagement occurs, the lower end 16 of the kelly portion 12 of the tubular member will engage the body shoulders 17 and the lock and expander 38 on the tubular member 33 will be disposed behind and in engagement with the lock portions 32 on the cutter supporting members 26, as illustrated in FIGS. 6 and 7.

Relative movement between the tubular mandrel 10 and the body 13 of the tool is accomplished hyraulically in the specific form of apparatus disclosed in the drawings. Thus, the piston or enlarged portion 18 on the drill stem 12 is received within a counterbore 51 in the upper portion of the body of the tool. This upper portion actually constitutes a cylinder 52 having a cylindrical Wall 53 extending from the lower shoulder 54 defining the bottom of the counterbore 51 to the cylinder head 19.

A confined cylinder space 55 is formed between the piston portion 18 of the kelly, the periphery of the kelly above the piston, and the cylinder 52. A suitable packing or side seal ring 56 may be disposed in a suitable piston ring groove 57 formed in the piston portion 18, which is adapted to slidably seal against the cylindrical wall 53 of the cylinder 52. Fluid is thereby prevented from passing in a downward direction between the piston and cylinder. Similarly, fluid is prevented from passing in an upward direction out of the annular cylinder space 55 by an inner side seal ring 58 carried in an internal groove 59 in the cylinder head 19 and slidably and sealingly engaging the periphery of the kelly 12 above the piston 18, and also by an outer side seal ring 60 disposed in an external groove 61 in the head 19 and sealingly engaging the cylinder wall 53.

Fluid under pressure in the string of drill pipe B and in the tubular mandrel passage 45 can be fed into the cylinder space 55 through one or more side ports 62 establishing communication between the central passage 45 through the kelly and the cylinder space. Such fluid under pressure is developed, in the form of invention disclosed in the drawings, by virtue of the fact that the total area through the jets or nozzles 103, 107 in the lower portion of the body 13 and in the drill bit K secured to the body is substantially less than the area of the passage 45 through the kelly portion of the mandrel, or because of the fact that the passage 46 through the tubular member 33 of the mandrel is of a restricted diameter as compared to the passage 45. As a result, the pumping of drilling mud or other fluid at an adequate rate through the apparatus will build up a back pressure of fluid in the passage 45, which pressure will be imposed on the fluid in the cylinder space 55, acting upon the cylinder head 19 to urge the body 13 of the tool in an upward direction with respect to the tubular mandrel 10, to secure outward expansion of the cutter supporting members 26 and cutter structures 29 to their fullest extent, a above described.

As apparently dis-closed in the drawings, a set of diametrically opposed supporting members 26 and cutter structures 29 is supplied and arranged substantially 180 degrees from each other. Actually, it is preferred to supply three sets of supporting members and cutter structures displaced substantially 120 degrees from each other to secure a smoothly running apparatus. The two sets of supporting member structures 26, 29 are shown in the drawings in the interest of simplicity of illustration. However, regardless of the number of cutters used, the generally radial jet nozzles 103 employed can be of any suitable number disposed circumferentially from one another to the desired extent, and also, if desired, displaced somewhat axially with respect to one another.

When the casing or conduit D is to be severed at a particular location in the well bore and along a desired length for the purpose of depositing a cementitious plug therein, the apparatus A is run in the well casing with the cutter supporting members 26 and the cutter structures 29 in their initial retracted positions, such as disclosed in FIGS. 5a and 5b. When the apparatus has been lowered to the desired point in the well casing at which the latter is to be severed, the pumps (not shown) at the top of the well bore are started to pump fluid at a suflicient rate through the drill pipe B and into the mandrel passages 45, 46, and through the body nozzles 103 and drill bit nozzles 107, building up a back pressure in the kelly passage 45, the port 62 and cylinder space 55, which pressure acts upon the cylinder head 19 to urge the body 13, the cutter supporting members 26 and the cutter structures 29 in an upward direction with respect to the mandrel 10. During such upward movement, the expander surfaces 30 are brought to bear against the lock and expander portion 38 of the mandrel, the cutter structures being urged in an outward direction against the wall of the well casing D. The drill pipe B and the apparatus A are rotated at the proper speed while fluid is being pumped through the apparatus, the outer edges of the cutters 2'9 acting upon the wall of the casing and gradually milling it away, as described in United States Patent No. 2,922,627, for example. During this operation, the apparatus is retained in substantially the same longitudinal position in the well casing. As the casing is cut away, the hydraulic force acting upon the body 13 raises it and the cutter supporting members 26 and cutter structures 29 to a further extent, until the outer edges of the cutters have completely severed the casing. Thereafter, rotation of the drill pipe B and the apparatus A continues so that the reaming portions of the cutters 29 continue to cut awaythe casing and dig into the formation until the cutters have been fully expanded outwardly to the maximum extent, as determined by coengagement of the stop shoulders 49, 50 and the lower end 16 of the kelly portion 12 of the mandrel with the body shoulders 17. With the parts in thisposition, the lock portions 32 of each cutter supporting member 26 will bear against thelock and expander portion 38 of the tubular member 33 to preclude'the inadvertent partial retraction of the cutter structures 29 from their fully expanded positions.

Downweight in the proper amount is now imposed on the string of drill pipe B, this downweight being transmitted through the kelly 12 to the body shoulder 17 and from the body 13 to the stop shoulders 50,49 and directly to the cutter supporting members 26 and the cutter structures 29, urging the latter against the upwardly facing severed end E of the well casing. The imposition of the proper downweight or drilling weight on the apparatus and its rotation at the proper speed will cause the cutters to eifect a cutting action upon the severed end E of the casing and mill it away, as shown in FIG. 1. During such milling action, drilling fluid is being pumped down through the drill pipe 10 and chamber 101, discharging from the body nozzles 103 and the drill bit nozzles 107 intothe well bore, carrying the cuttings upwardly around the apparatus A and the drill pipe B to the top of the hole.

During the operation of milling away the casing in a downward direction, the upper end E of the casing will wear away the milling cutter or drag structure 29 by cutting an upwardly extending groove 110 therewithin. If milling of the casing by the set of cutters 29 continues. for too long a time, such progressive formation of the groove 110 in the cutter blades may continue until the casing cuts completely through the cutter structures, severing their outer portions 29a from theirinner portions 29b, at which time the longitudinal outer surfaces 290 of the remaining cutter structures 2% will have the same diameter as the inside diameterof the well casing D.

After the desired length of casing has been milled away, which, for example, may be of the length of 20 feet to 40 feet, the downweight imposed on the apparatus is discontinued. A subsequent-operation can now be performed in B and through the mandrel thewel'l bore without removing the apparatus A from the well bore. Preferably, as shown in FIG. 2, the well bore is conditioned by pumping circulating fluid down through the drill pipe B and through the apparatus A, discharging from the radial nozzles 103 which direct jets of fluid against the wall of the exposed well bore M. The drill string and apparatus connected thereto are rotated at the desired speeds during such pumping operation, so that the entire circumference of the well bore is covered by the 1 jets of fluid issuing from the nozzles 103; During the rotation andpumping operation, the drill pipe B and the apparatus A can be gradually ele-vatedfrom a lowermost end of the exposed bore hole streams are caused to impinge upon the desired length of the wall of the well bore above the lower shoulder E produced by the cutters. If, for example, the well casing D has been severed along may be elevated a distance of about 20 feet so that the jets discharge fluid along the entire length of the exposed hole M. Of course, the apparatus can be raisedand lowered as many times as desired.

The elevation of the apparatus A while fluid is being pumped through it and the apparatus rotated by the drill pipe will cause the fluid jets to act against the wall of the exposed well bore to remove the drilling mud cake therefrom. If desired, not only can the mud cake be removed, but the fluid jet may be employed for effecting a hydraulic enlarging of the diameter of the exposed well bore M (FIG. 2).

Assuming the well bore to have been conditioned by pumping fluid through the nozzles 103, a cement plug may be formed therein, as by pumping the proper amount of cement slurry S down through the drill pipe B, passing through the mandrel passage 45, 46 and into the body chamber 101, then discharging through the radial nozzles 103 against the wall of the hole, as well as through the drill bit nozzles 107. As the cement is discharged from the nozzles, the drill pipe B andthe apparatus A are gradually elevated in the well bore from the lower region of the exposed hole M, while the drill pipe and the apparatus are rotated at a proper speed to insure uniform deposition of cement slurry S in the well bore, the latter sloughing downwardly to completely fill the entire crosssectional area of the well bore and along the desired length of the latter. As disclosed in FIG. 3, a cement plug is thereby formed along the entire length of the well bore M, and, in fact, extends upwardly into the well casing D thereabove- It is to be understood, however, that the upper end of thecement plug may terminate in the enlarged well bore M substantially below the lower end of the well casing thereabo-ve.

The cement slurry pumped down through the drill pipe 1 B is followed by a suitable displacement fluid. After all M, so that the jet or fluid a "length of about 20 feet, the tool of the required cement slurry has been discharged from the nozzles, the apparatus is elevated above the deposited slurry S and displacement or washing fluid forced through the apparatus A and its nozzles 103, 107 to clear all passages of the apparatus and all regions of the tool of cement slurry. The tool may require elevation above the mass of cement slurry S deposited in the open well bore as a plug, or even above the plug S extending upwardly into the lower portion of the upper well casing D. During such upward flushing of the excess cement slurry from the casing, a certain portion thereof will adhere to the wall of the casing above the severed section and harden thereon as a cement coating or sheath.

Following flushing of the excess cement slurry from the well bore, the pumping action can be stopped, which will relieve the pressure in the apparatus, allowing the body 13 of the tool to drop downwardly along the mandrel 10, the cutters 29 retracting and placing the apparatus A in condition for removal through the well casing D to the top of the well bore. However, such removal need not occur at this time, and preferably does not occur. Instead, the apparatus cleared of cement slurry is allowed to remain suspended in the well casing a convenient distance in the casing above the upper end of the cementitious material S deposited in the Well bore, as disclosed in FIG. 3.

The, deposited cement or cementitious material is allowed to set and harden in the well bore, forming the cement plug S therein. This plug remains in place and cannot be displaced particularly in a downward direction, since its outer margins are resting upon the lower formation shoulder E produced by the cutters in the well bore. The cement plug will extend laterially beyond the internal diameter of the well casing D, insuring against downward dislodgment of the cement plug in the well bore, as under the subsequent drilling action of a drill bit, including the drill bit K attached to the lower end of the bit body 13, or under the drilling action of a drill bit (not shown) which is deflected laterally by a whipstock (not shown) set in the well bore upon the cement plug.

After the cement plug is set and hardened, it is desired to determine that the upper end of the plug S is at the required location in the well bore below the upper end of the exposed well bore M, so as to allow the whipstock to be set thereon. However, the upper end of the cement plug may be at too high an elevation in the well bore, and, in fact, as illustrated in FIG. 3, may actually extend upwardly into the well casing above the exposed well bore. The drill pipe B and apparatus A can be lowered in the well casing until the drill bit engages the upper end of the cement plug S, which will indicate its location to the operator at the top of the well bore. If the upper end of the plug is found to be too high, the drill pipe string and apparatus are rotated at the proper speed and an appropriate drilling weight imposed on the apparatus to cause the drill bit K to act upon the plug and drill it away, drilling fluid being pumped through the drill string and the apparatus during this time, which will result in elevation of the body 13 along the mandrel 10 of the expansible drill bit to expand the cutters 29 outwardly against the wall of the well casing. Since the drill bit K usually has an effective drilling diameter slightly less than the inside diameter of the casing D, such bit cannot remove all of the cement within the casing, nor can it even act effectively upon the cement sheath that remains adherent to the wall of the well casing above the plug as a result of flushing excess cement slurry from the well casing. The expansible cutters 29, however, will engage the wall of the well casing and effect a scraping action thereon to remove the cement sheath, the cement particles from the casing sheath, as well as the cuttings from the cement plug S produced by the drill bit K, being flushed by the drilling fluid upwardly around the apparatus A and the drill pipe B to the top of the well bore. In

fact, at the commencement of the operation of drilling out a portion of the cement plug S, the apparatus may be elevated a desired distance in the well casing and rotated while circulating fluid is being pumped downwardly through the drill pipe and apparatus to cause the elevation of the body 13 along the mandrel and outward expansion of the cutters 29 against the Wall of casing, the

drill pipe and apparatus then being gradually lowered to cause the expanded cutters 29 to scrape the cement sheath from the wall of the well casing. When the bit K engages the upper end of the cement plug S, it will commence drilling such cement plug out while, at the same time, the expanded cutters 29 are scraping the wall of the well casing to remove the adherent cement sheath or coating that the drill bit K was incapable of removing.

Drilling out of the cement plug S by the drill bit K will continue until the drill bit is at the desired depth in the plug at which the whipstock is to be set, such as disclosed in FIG. 4. When the expanded cutters 29 enter the cement plug at the upper end of the exposed well bore M, they will slightly enlarge the diameter of the hole through the plug produced by the 'bit K, in the event that the outer portions 29a of the milling cutters have been completely severed by the well casing D as a result of the casing milling operation, to insure an adequate diameter of hole in the cement plug that will allow subsequent free downward movement by the whipstock into the plug.

In the event the milling cutter structures or drag cutters 29 were not completely severed, the hydraulic force acting upon the body 13 and tending to elevate it upon the mandrel 10 will still result in outward expansion of the cutters 29 against the wall of the well casing, such cutters being effective for scraping the cement sheath, and other foreign substances, from the wall of the well casing, as well as to at least slightly enlarge the bore in the cement plug S produced by the drill bit K. With the outer portions 29a of the cutters severed from the inner portions 29b, a substantial length of each cutter structure portion 29b is effective for scraping action upon the wall of the well casing, to insure its being placed in a clean condition, so that no cement sheath remains for interference with subsequent equipment that might be run in or set in the well casing.

In the event that the cement plug S deposited along the exposed wall of the well bore M has not risen too high, as determined by subsequent engagement therewith by the drill bit K, the rotation of the apparatus A by the drill pipe B while fluid is being pumped downwardly therethrough will still efiect a scraping by the expanded cutters 29 of the wall of the well casing during the time the apparatus is in the casing above the hole M.

After the casing D has been scraped and the cement plug placed in condition for reception of the whipstock at the proper location, as disclosed, for example, in FIG. 4, or in the event the cement plug did not require any drilling out for reception of the whipstock thereupon, pumping of fluid through the drill pipe B and apparatus A can cease, permitting the body 13 and cutters 29 to drop downwardly along the mandrel 10, the cutters shifting laterally inwardly to a retracted position, whereupon the drill pipe and apparatus can be elevated in the well Roge M and easing D and withdrawn to the top of the By virtue of the apparatus and method illustrated and described, not only can the well casing or liner D be milled away to expose the well bore M, the hole then being properly conditioned, and a cementitious plug S deposited therein, but the same apparatus A, in the same trip in the well bore C, can be used to determine the location of the upper end of the hardened cement plug S, such cement plug being drilled out to the desired depth if required, and the well casing D scraped above the cement plug, thereby effecting substantial economies in equipment cost and in time required for preparing the conduit therein, comprising lowering conduit cutting and fluid discharging apparatus in, the bore hole on a tubular drill string, rotating the drill stringand apparatus to cut,

the conduit awayalong a desired length in the bore hole to expose the. surrounding wall of the bore hole, pumping cementitious material down the drill string and through the apparatus laterally against the exposed wall of the well bore while rotating the drill string. and apparatus, pumping flushing fluid through the drill string and apparatus to clear the drill string and apparatus of cementitious material, and rotating and lowering the drill string and apparatus in the conduit above the exposed bore hole to scrape the wall of the conduit.

2. The method of conditioning a bore hole having a conduit therein, comprisinglowering conduit cutting and fluid discharging apparatus in the bore hole on a tubular drill string, the apparatus having expandible cutters, rotating the drill string and apparatus to cause the cutters to cut the conduit away along a desired length in the bore hole to expose the surrounding wall of the bore hole, pumping cementitious material down the drill string and through the apparatus laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping flushing fluid through the drill string and apparatus to clear the drill string and apparatus of cementitious material, and rotating and lowering the drill string and apparatus in the conduit above the exposed bore hole to cause the expandible cutters to scrape the wall of theconduit.

3. Themethod of conditioning a bore hole having a conduit therein, comprising lowering conduit cutting and fluid discharging apparatus in the bore hole on a tubular drill string, the apparatus having expandible cutters, rotating the string and apparatus to cause the cutters to cut the conduit away along a desired length in the bore hole to expose the surrounding wall of the bore hole and to cause the conduit to sever the outer portions of the cutters from their inner portions, pumping cementitious material down the drill string and through the apparatus laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping flushing fluid through the drill string and apparatus to clear the drill string :and apparatus of cementitious material, and rotating and lowering the drill string and apparatus in the conduit above the exposed bore hole to cause the inner portions of the severed expanded cutters to scrape the Wall of the conduit.

4. The method of conditioning a bore hole having a conduit therein, comprising lowering conduit cutting, bore hole drilling and fluid discharging apparatus in the bore hole on a tubular drill string, rotating the drill string and apparatus to cut the conduit away along a desired length in the bore *hole to expose the surrounding wall of the bore hole, pumping cementitious material down the drill string and through the apparatus laterally against the exposed wall of the borehole while rotating the drill string and apparatus, pumping flushing fluid through the drill string and apparatus to clear the drill string and apparatus of cementitious material, and rotating and lowering thedrill string and apparatus in the conduit above the exposed bore holeto scrape the wall of the conduit above the exposed bore hole and to drill away cementitious material in the bore hole.

5. The method of conditioning a bore hole having a conduit therein, comprising lowering conduit cutting, bore hole drilling and fluid discharging apparatus in the bore hole on a tubular drill string, rotating the drill string and apparatus to cut the conduit away along a desired length in the bore hole to expose the surrounding wall of the bore hole, pumping cementitious material down 1 6 the drill string and] through the apparatus laterally against the exposed wall oi the bore hole'while rotating a. and lowering the drill string and apparatus inthe conduit above the exposed lbore'hole to scrape the wall of the conduit above the exposed bore holeand to drill away cementitious material in? the conduit above the exposed bore hole, and continuing rotation and'lowering of the apparatus to drill out at least a portion of the cementitious material deposited in the exposed portion of the bore hole. 1

6. The method of conditioning a bore hole having a conduit therein, comprising lowering conduit cutting, bore hole drilling and fluid discharging apparatus in the bore hole on a tubular drill string, the i apparatus having expandible cutters, rotating the drill. string and apparatus to cause the cutters to cut the'conduit away along a desired length in the bore hole to expose the surrounding 'wall of the bore hole; pumping cementitious material down the drill string and throughthe apparatus laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping flushing fluid through the drill string andapparatus to clear the drill :string and apparatus of cementitious material, and rotating and lowering the drill string and apparatus in the conduit above the exposed borehole to cause the expandible cutters to scrape the wall of the conduit and to drill away cementitious; material in the bore hole. 7. The method of conditioning a bore hole having a conduit therein, comprising lowering conduit cutting, bore hole drilling and fluid discharging apparatus in the bore hole on a tubular drill string, the apparatus having expandible cutters, rotating the drill string and apparatus to cause the cutters to cut the conduit away along a desired length in the bore hole to expose the surrounding wall of the bore hole, vpumping cementitious material down the drill string and through the apparatus laterally against the exposed wall of the bore hole While rotating the drill string and apparatus, pumping flushing fluid through the drill string and apparatus to clear the drill string and apparatus of cementitious material, rotating and lowering the drill string and apparatus in the conduitabove the exposed bore hole to cause the expandible cutters to scrape the wall of the conduit above the exposed bore hole and to drill away cementitious material in the conduit above the exposed bore hole, and continuing rotation and lowering of the apparatus to drill out at least a portion of the cementitious material deposited in the exposed portion of the bore hole.

8. The method of conditioning a bore hole having a conduit therein, comprising lowering conduit cutting and fluid discharging apparatus in the :bore hole on a tubular drill string, rotating the drill string and apparatus to cut the conduit away along a desired length in the bore hole to expose the surrounding wall of the bore hole, pumping washing fluid down the drill string and discharging the washing fluid laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping cementitious material down the drill string and through the apparatus laterially against the exposed wall of the well bore While rotating the drill string and apparatus, pumping flushing fluid through the drill string and apparatus to clear the drill stringand apparatus of cementitious material, and rotating and lowering the drill string and apparatus in the conduit above the exposed bore hole to scrape the wall of the conduit.

9. The method of conditioning a bore hole having a conduit therein, comprising lowering conduit cutting and fluid discharging apparatus in the bore hole on a tubular drill string, the apparatus having expandible cutters, rotating the drill string and apparatus to cause the cutters to cut the conduit away along a desired length in the bore hole to expose the surrounding wall of the bore hole,

pumping washing fluid down the drill string and discharging the. washing fluid laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping cementitious material down the drill string and through the apparatus laterally against the exposed wall of the borehole while rotating the drill string and apparatus, pumping flushing fluid through the drill string and apparatus to clear the drill string and apparatus of cementitious material, and rotating and lowering the drill string and apparatus in the conduit above the exposed bore hole to cause the expandible cutters to scrape the wall of the conduit.

10. The method of conditioning a bore hole having a conduit therein, comprising lowering conduit cutting and fluid discharging apparatus in the bore hole on a tubular drill string, the apparatus having expandible cutters, rotating the string and apparatus to cause the cutters to cut the conduit away along a desired length in the bore hole to expose the surrounding wall of the bore hole and to cause the conduit to sever the outer portions of the cutters from their inner portions, pumping washing fluid down the drill string and discharging the washing fluid laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping cementitious material down the drill string and through the apparatus laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping flushing fluid through the drill string and apparatus to clear the drill string and apparatus of cementitious material, and rotating and lowering the drill string and apparatus in the conduit above the exposed bore hole to cause the inner portions of the severed expanded cutters to scrape the wall of the conduit.

.11. The method of conditioning a bore hole having a conduit therein, comprising lowering conduit cutting, bore hole drilling and fluid discharging apparatus in the bore hole on a tubular drill string, rotating the drill string and apparatus to cut the conduit away along a desired length in the bore hole to expose the surrounding wall of the bore hole, pumping washing fluid down the drill string and discharging the washing fluid laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping cementitious material down the drill string and through the apparatus laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping flushing fluid through the drill string and apparatus to clear the drill string and apparatus of cementitious material, and rotating and lowering the drill string and apparatus in the conduit above the exposed bore hole to scrape the wall of the conduit above the exposed bore hole and to drill away cementitious material in the bore hole.

12. The method of conditioning a bore hole having a conduit therein, comprising lowering conduit cutting, bore hole drilling and fluid discharging apparatus in the bore hole on a tubular drill string, rotating the drill string and apparatus to cut the conduit away along a desired length in the bore hole to expose the surrounding wall of the bore hole, pumping washing fluid down the drill string and discharging the washing fluid laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping cementitious material down the drill string and through the apparatus laterally against the exposed wall of the bore hole while rotating the drill string and apparatus, pumping flushing fluid through the drill string and apparatus to clear the drill string andapparatus of cementitious material, rotating and lowering the drill string and apparatus in the conduit above the exposed bore hole to scrape the wall of the conduit above the exposed bore hole and to drill away cementitious material in the conduit above the exposed bore hole, and continuing rotation and lowering of the apparatus to drill out at least a portion of the cementitious material deposited in the exposed portion of the bore hole.

13. In apparatus adapted to be lowered on a tubular drill string in a conduit disposed in a bore hole: a rotary drill bit having expandible milling cutting means for milling away a length of the conduit after the bit has been lowered in the conduit, said bit having a fluid passage adapted to receive fluid from the tubular string; means secured to said bit to receive fluid from said passage and direct such fluid laterally against the wall of the bore hole without impinging on said cutting means; and a lower drill bit secured to the lower end of said rotary drill bit, said lower drill bit having a fluid passage communicating with said other passage.

14. In apparatus adapted to be lowered on a tubular drill string in a conduit disposed in a bore hole: a body; expandible milling cutter means on saidbody for milling away a length of the conduit after the bit has been lowered in the conduit; a mandrel movable longitudinally in said body and having a passage adapted to receive fluid from the drill string; coengageable expander means on said mandrel and cutter means for expanding said cuttermeans in response to relative longitudinal movement between said body and mandrel; said body having a chamber into which said mandrel discharges fluid; a generally radial nozzle secured to said body and communicating with said chamber to receive fluid therefrom and discharge said fluid against the wall of the bore hole; the lower end of said body having a threaded connector portion communicating with said chamber; and a drill bit having its upper end threadedly attached to said connector, said drill bit having fluid passage means communicating with said chamber.

15. In apparatus adapted to be lowered on a tubular drill string in a conduit disposed in a bore hole: a body; expandible milling cutting means on said body for milling away a length of the conduit after the bit has been lowered in the conduit; a mandrel movable longitudinally in said body and having a passage adapted to receive fluid from the drill string; coengageable expander means on said mandrel and cutter means for expanding said cutter means in response to relative longitudinal movement between said body and mandrel; a generally radial nozzle secured to said bit below said cutter means and adapted to discharge fluid received from said mandrel passage laterally against the wall of the well bore; the lower end of said body having a threaded connector portion communicating with said passage; and a lower drill bit having its upper end threadedly attached to said connector portion, said lower drill bit having fluid passage means communicating with said other passage.

References Cited by the Examiner UNITED STATES PATENTS 2,758,819 8/1956 Kammerer -267 3,083,765 4/1963 Kammerer l6621 3,126,065 3/1964 Chadderon 175269 3,196,960 7/1965 Kammerer 175267 CHARLES E. OCONNELL, Primary Examiner. D. H. BROWN, Assistant Examiner. 

1. THE METHOD OF CONDITIONING A BORE HOLE HAVING A CONDUIT THEREIN, COMPRISING LOWERING CONDUIT CUTTING AND FLUID DISCHARGING APPARATUS IN THE BORE HOLE ON A TUBULAR DRILL STRING, ROTATING THE DRILL STRING AND APPARATUS TO CUT THE CONDUIT AWAY ALONG A DESIRED LENGTH IN THE BORE HOLE TO EXPOSE THE SURROUNDING WALL OF THE BORE HOLE, PUMPING CEMENTITIOUS MATERIAL DOWN THE DRILL STRING AND THROUGH THE APPARATUS LATERALLY AGAINST THE EXPOSED WALL OF THE WELL BORE WHILE ROTATING THE DRIL STRING AND APPARATUS, PUMPING FLUSHING FLUID THROUGH THE DRILL STRING AND APPARATUS TO CLEAR THE DRILL STRING AND APPARATUS OF CEMENTITIOUS MATERIAL, AND ROTATING AND LOWERING THE DRILL CEMENTIAND APPARATUS IN THE CONDUIT ABOVE THE EXPOSED BORE HOLE TO SCRAPE THE WALL OF THE CONDUIT. 